Workers form counterforts at the rear abutment of a new structure that will carry I-70 over the future ramp from I-71 South to I-70 East. Photo courtesy of Bruce Hull, Ohio Department of Transportation

The Columbus Crossroads Project aims to curtail major traffic congestion and safety risks by modernizing outdated infrastructure in Columbus, the largest city in Ohio. The ambitious, multi-decade plan calls for the reconstruction and reconfiguration of several critical areas, including one of the state’s most notorious freeway crash sites: the “Downtown Split,” a 1.25-mile overlap of I-70 and I-71 that runs through the bustling central business district in downtown Columbus.

Outdated Freeway Design Leaves Room for Improvement

The convergence of I-70 and I-71 (Downtown Split) at the heart of Columbus is as a vital point of entry to the city for tens of thousands of daily commuters and visitors. Furthermore, these nationally significant routes provide an essential link for domestic freight movements between the East Coast and the Midwest, and also support and advance local and regional economic development.

Improving travel reliability and safety at the Downtown Split is the crux of the Columbus Crossroads Project. Today, the project corridor serves approximately 130,000 vehicles per day, including 17,000 trucks. It not only exceeds its original design capacity by about 50,000 vehicles each day, but also is the only area in the state where I-70 and I-71 are reduced to one lane for through traffic, which further complicates traffic movements.

While the Downtown Split comprises only 6 percent of the Columbus area freeway system, it is the site of 25 percent of all freeway crashes in the region, resulting in an average of two crashes per day. Many of these crashes are caused either by congestion or are the result of an outdated design scheme (the Downtown Split was built in the 1960s).

These are some of the key factors leading to the development of Columbus Crossroads, which casts an ambitious vision for the freeways and urban avenues that move through and connect the Columbus region. The Ohio Department of Transportation (ODOT) is spearheading the development of this $1.3 billion megaproject, which has been under construction since 2011.

Besides untangling the overlapping sections of freeway, crews are working to consolidate ramps and improve circulation on downtown city streets. Once the entire project is completed, there will be an additional thru lane on I-70 and I-71 helping to alleviate traffic and enhance safety for motorists traveling through the downtown area.

ODOT, along with partners at the City of Columbus, the Mid-Ohio Regional Planning Commission (MORPC), and a diverse group of community stakeholders and business entities have collaborated to develop and implement this vision over the last 15 years. The project team’s comprehensive and intensive public involvement plan has included over 500 community meetings and thousands of public comments – all part of a shared desire to build broad-based support of this transformative project.

In addition to ODOT’s $1.3 billion backing, MORPC has contributed $20 million and the City of Columbus has contributed $40 million directly to the project as well as an additional investment in the surrounding area valued near $60 million.

Tight Constraints, Big Challenges

A large, multifaceted project such as this has many inherent challenges, including coordination with adjacent projects and local stakeholders to avoid negatively impacting other activities and community members and businesses. For the Columbus Crossroads design and construction team, however, the biggest obstacle is the scale of the project and the limited amount of space to complete it in.

“Designing the project was like threading the needle to fit traffic through the corridor,” says ODOT Project Engineer Leslie Montgomery. “It was difficult to find space without adversely impacting downtown businesses. You’ve got the historic Brewery District and the iconic smokestack, the Franklin County Courthouse, schools, churches, and other businesses. It’s a delicate balance.”

One solution to the limited real estate is to construct full-height retaining walls instead of the traditional slopes used previously. This way, ODOT can add the lanes that are needed, but still use the existing freeway footprint.

When it comes to construction, space is challenging because there’s little room for laydown and material storage. ODOT Construction Project Engineer Natina Ariss comments, “The contractor has had to be very creative when it comes to material storage. Instead of hauling dirt off-site, we’re gathering a large pile in the middle of the project and storing materials on sections of roadway that have been closed.”

And along with finding room for materials, space is also needed to maintain traffic and place signs to direct drivers on where to go. For the current traffic pattern on I-70 East through downtown, ODOT placed pavement tattoos in the lanes to supplement the overhead signs.

“There’s the physical constraint – for example, that building’s in your way,” Montgomery says. “But there’s also the human constraint. When we change a traffic pattern, drivers need time to figure out what to do.”

Identifying and managing utility conflicts present another frustrating set of obstacles that can potentially slow progress, increase costs and create safety hazards. “Utility conflicts during construction are always an issue,” Ariss remarks, “but particularly in such an urban setting when we’re dealing with city streets as opposed to freeways. The age of Columbus’ infrastructure and resulting lack of records means the potential for more unknown utilities and often, a longer timeframe before it’s resolved. The key to dealing with these types of conflicts is prompt communication and good partnerships.”

Current and Future Construction Highlights

The Columbus Crossroads Project is currently divided into 19 phases of construction. It was originally split into phases based on geographic location, but ODOT rephased the projects in 2015 to prioritize the movements that would make the biggest safety and congestion improvements. The five projects that ODOT prioritized will reduce lane changes through downtown by 90 percent.

Phase 2E, which has been underway since April 2019, will reconstruct and widen I-70 East between 4th Street and Miller Avenue, build new ramps from Fulton Street to I-70 East and from I-70 East to Parsons Avenue, reconstruct Mooberry Street from Parsons Avenue to 18th Street, reconstruct Fulton Street from 3rd Street to 4th Street, and build eight retaining walls. Project officials anticipate this phase of work will require 240,200 cubic yards of excavation, 15,500 cubic yards of asphalt, a total 3.7 million pounds of rebar for retaining walls and bridges, and 29,000 cubic yards of concrete.

Slated for completion in October 2021, Phase 2E is being funded by ODOT’s TRAC (Transportation Review Advisory Council) at a cost of $81 million. The key members of the design and construction team include Kokosing Construction Company (general contractor), MS Consultants (lead design consultant) and DLZ (primary structural consultant). Other noteworthy project consultants include Columbus Engineering Consultants, HNTB, MKSK (formerly known as MSI Design) and PRIME AE Group (formerly known as Prime Engineering).

Ultimately, roadway upgrades in Phase 2E will build on past efforts – and support future endeavors – to improve urban design and gateways, roadway safety, capacity, connectivity and aesthetics throughout the interchange corridor. “It’s important to remember that this project (2E) is part of a bigger picture,” Montgomery emphasizes. “And we’re not only dramatically improving safety and congestion on the freeways, we’re also making huge improvements to city streets by reconnecting neighborhoods and building complete streets that will be safer for pedestrians, cyclists and transit users, including people of all ages and abilities.”

The next three phases of construction are also fully funded. Phases 3B and 4R are expected to start in April 2020 and June 2020, respectively, and Phase 6R will likely begin sometime next year. Combined, this cluster of projects represents an investment of approximately $282 million.

Other future phases of Columbus Crossroads are still in developmental stages. ODOT representatives currently anticipate the project to be finalized in 2037. However, the construction timeline could move up if funding for the remaining phases becomes available in a timely manner.

“This project is literally transforming downtown Columbus, and it gives me great satisfaction not only to watch it happen, but to be a part of it,” Ariss says. “It’s ultimately going to make movement through this area a lot easier and a lot safer.”

Montgomery concurs. “This is a modern and happy marriage of freeway engineering for the safe and efficient movement of goods and people, with urban planning for livable communities and it really serves as a model,” she emphasizes. “Planners, designers and stakeholders have expressed so much pride and gratitude for the opportunity to be involved with this once-in-a-lifetime project.”